While U.S. Pat. No. 2,891,920 (Jun. 23, 1959) and U.S. Pat. No. 3,294,725 (Dec. 27, 1966) each teach the use of condensation specific acid catalysts for polymerizing oligomers to siloxane polymers of higher viscosity and/or higher molecular weight, neither patent suggests that siloxane polymers exhibiting improved release properties can be obtained by including in the process an alkyltrialkoxysilane R'Si(OR").sub.3 where R' and R" represent alkyl groups, and R' contains at least eight, preferably at least twelve, and most preferably at least sixteen or more carbon atoms.